Lamp holder



April 29, 1941.lv R YQUNG ML 2,240,200

LAMB HOLDER VFiled uaylfa., 1939 a lvets: Wil'I-ar RYOUHQ, A Frank DB1*`'antw y Their Attorney Patented Apr. 29, 1941 LAMP HOLDER william R.Young, Fairfield, and Frank p. Bryant, Stratford, Conn., assignors toGeneral Electric Company, a corporation of New York Application May 12,1939, Serial No. 273,256

2 Claims. (Cl. 173-354) This invention relates to lamp holders forincandescent lamps, and more particularly to lamp holders provided withswitch mechanism for controlling the supply of current to the lamp.

The object of the invention is to provide an improved construction andarrangement in lamp holders of the type described in which the switchmechanism is of simplified and rugged construction which may be easilyassembled and manufactured at low cost.

In the accompanying drawing, Fig. 1 is an elevational view of the lampholder; Fig. 2 is a view of the interior of the lamp holder showing theswitch mechanism; Fig. 3 is another View yof the interior of the lampholder with a portion of the switch mechanism removed; Fig. 4 is a.sectional view through the lamp holder along the line 4-4 of Fig. 3;Fig. 5 is another sectional view through the lamp holder along the line5-5 of Fig. 3; Fig. 6 is an exploded view showing the elements of theswitch mechanism; and Figs. 7 to 10, inclusive, are diagrammatic viewsshowing the different positions of the switch mechanism in controllingan electric current to the lamp holder.

Referring to the drawing, the lamp holder is provided with a cylindricalhousing IUI formed with an annular shoulder I I on the interior wallthereof to receive a supporting member or base I2.' The base conforms tothe configuration of the housing and rests upon the shoulder II in whichposition it is held by fastening means such as screws I3, as shown byFig. l. A cover I4 closes one end of the housing. The elements thus fardescribed are made of insulating material, for example, a phenoliccondensation product and filler. The base I 2 supports a switchmechanism on one side and a lamp socket means on the other side.

The lamp socket means is supported from the lower side of the basemember and includes a screw shell receptacle I5, an intermediate contactmember I6 and a center contact member II. By this construction the lampsocket is adapted to receive a two-filament lamp but manifestly thesocket may be adapted to receive a single filament lamp by omitting oneof the contact members, usually the intermediate contact member. thebase by screws I8 and I9 passing through ears 20 formed integrally withthe shell and which are bent over to engage the face of the base memberI2. InA order to support the intermediate contact member l6, the basemember is formed with an integral annular flange 2I The screw shell ismounted on depending from the lower face thereof and forming a recess22. The intermediatek contact member is shaped as an annulus and restsupon the surface of the flange, the latter forming a bearing surface forthe contact member, a tang or projection 23 is formed integrally withthe annulus and is secured to the base by a screw 24 to hold the contactmember in position. The center contact member comprises a nat springstrip secured at one end to the base I2 by a screw 25 and the other endextends through a slot 26 in the flange 2| to a point at the center ofthe annular intermediate contact member within the recess 22. In thismanner, the center and intermediate contact members are insulated fromone another. A coiled spring 21 bears at one end against the centerycontact and at the other end against the base of the recess to resistdeflection of the contact member upon engagement with the base of a lampthereby maintaining gocd electrical contact with the base of the lamp.

The switch mechanism includes stationary contacts located on the uppefiside of the base I2 and electrically connected to the lamp socket means.As shown most clearly by Fig. 6, the upper face of the base is providedwith an annular series of cam surfaces 28, 29, 30 and 3| formingadjacent hills and valleys for receiving the movable contacts, to bedescribed hereinafter. Each of the cam surfaces 29, 30 and 3I is formedwith a slotted or recessed portion to receive corresponding contacts 32,33 and 34. The hill portions of the cam surfaces separate the contactsfrom one another. Each of the contacts is formed with a valley portioncorresponding to and mating with the corresponding valley of the camsurface so that a continuous cam surface having alternate hills andvalleys is formedJ by the contacts and cam surfaces 28. The assembledarrangement of these elements is-shown by Fig. 3. The contact 32 isprovided with an integral extension or terminal 35 fitting within arecess 36 formed in the base I2 and secured to the base by means of ascrew 31. In order to provide for lthe connection of an electricalconductor, a terminal screw 38 is mounted on the extension 35. Thecontact 33 is formed with an integral arm 39 curving around the side ofthe adjacent camsurface and an lextension 40 resting in a recess 4Iprovided in the face of the base. The extension is formed with anopening 42 for receiving the screw 25 which holds'the center contact I1on the base. In this manner the contact 33 is electrically connected tothe in a recess 44 in the face of the base. An opening :i is formed inthe extension Vfor receiving the screw 24 which holds the intermediatelamp 5 contact in position on the base.V In this manner the contact 34is connected electrically to the intermediate contact of the lampsocket. A terminal member 45 is seated within a recess 41 in the baseand is provided with a terminal screw for receiving an electricalconductor. An. opening 49 in the 'terminal member receives the screw I5which holds the socket shell in lposi` tion on the base. In this mannerthe terminal `member 45 is connected electrically to the 1 threadedshell I5 of the lamp socket means.

'I'he switch mechanism also includes movable contact means cooperatingwith the iixed contacts. As shown most clearly by Figs 4 and 6, theupper face of the base I2 is formed with a bearing surface 55 whichsupports a rotatable element'5l of insulating material secured in position by a bolt 52. 'I'he rotatable element is of substantiallycircular shape and is provided around its outer pen'phery with a seriesoi cam faces forming teeth in the ratchet wheel corresponding to thenumber of valleys designated by the fixed contacts and the cam face 25,in this case, four. A series oi recesses or slots 54, 55, 55 and 51 arearranged in annular formation in the rotatable element adjacent theouter periphery thereof. The recesses 54, 55 and 55 extend into a groove55 which receives a metallic shorting member 53. In this manner, one endof each of the recesses 54, 55 and 55 is closed by the shortng memberwhile the corresponding end of the recess 51 is closed by the face ofthe rotatable element inasmuch as the latter recess does not extendthrough the member. The movable contacts are formed 'of ball bearings5D, 5I, 62 and 53 which are disposed within the recesses 54, 55, 56 and51, respectively. A coiled spring 54 is disposed between each of theball bearings and the closed end of the respective recess. This meansthat the roller contacts or ball Abearings 55, 5l and 52 are electncallyinterconnected by the shorting plate or member 55 and form live contactsin the circuit of the` switch while the ball bearing 53 is seated withinthe recess 51 in the insulating rotatable member and constitutes a deadcontact in the switch. The purpose of the ball bearing 53 is to provideanother bearing surface supplementing thelive contact ball bearings sothat the ratchet wheel rotates freely and easilyabout theV pin 53without tilting out of position. The springs 54 maintain the ballbearings nrmly in engagement with the xed contact members to secure aneffective electrical contact; at the same time, they permit the ballbearings to move longitudinally ci' the recesses as the ratchet wheel isrotated so that the ball bearings will easily pass over the hillsseparating the valleys in the nxed contact members. As shown mostclearly by Fig. 4, a plate 55 of insulating material covers the shortingmember 55 and is held in position by engagement with the head of thescrew 52, the body oi' the screw passing through an opening 55 in theplate. While the movable switch contacts have been shown and describedas ball bearings. it should be manifest that other forms of rotatablecontacts may be employed, for example, cylindrical members. A

The switch mechanism further includes operating means for the movablecontacts. An 'op- 75 erating member or pawl 51 is secured to one end oia bead chain which end, in turn,is Iastenedtoaspring attachedtothebaseI2 by a pin or screw 1l. As shown bygFig. 2, the spring, pawl and chainare disposed around the outer periphery of the vratchet wheel with thepawl in engagement with. one of the teeth 53 and with the end of thechain passing through a guide 1I to the outside oi the housing of thelamp holder. 'Rotation of the ratchet wheel is limited by enlarged beadsformed in the bead chain 55; the enlarged bead 12 limits thecounterclockwise rotation of the ratchet wheel, as shown in I Fig. 2,and thereby the extension oi the spring 59, while the enlarged bead 13limits the clockwise rotation of the ratchet wheel and the retraction ofthe spring 53. In each case the enlarged bead engages the respectivewall of the guide 1I. The degree of angular movement of the rotatablemember or ratchet wheel is, oi course. limited and deilned by theportions of the valleys in the fixed contact members. The tension in thespring normally maintains the bead chain and pawl in close engagementwith the outer periphery of the rotatable member so that the pawl firmlyengages the respective cam face 53. Upon pull of the chain 55 the pawlengages one of the cam surfaces and moves the rotatable membercounterclockwise against the action of the spring until the ballbearings move over the hills into the adjoining valleys in the fixedcontact members, at which point the enlarged bead abuts the guide 1Ilimiting movement oi the chain. Upon release of the chain the spring 55retracts the pawl into engagement with the next succeeding cam face 53pulling the chain within the housing of the lamp holder until theenlarged bead 13 engages the guide 1I.

In the use of the device the conducting wires Li--In of an electricpower system are connected to the terminals 45 and 35, respectively, thewires passing through openings 14 in the cover I4, and a two-filamentlamp is threaded into the screw shell I5 so that the lamp terminalsengage the intermediate and outer contacts I 5 and I1. When the switch'mechanism is moved to the position shown tically by Fig. k7, one of thelamp iilaments is energized. Current ilows from line L1 through terminal45, screw I5, socket shell I5, the lamp nlament, intermediate contactI5, screw 24, ilxed contact 34, one of the ball bearing contacts andspring, shorting member 53,

' another of the ball bearing contacts and springs,

contact 32 having the integral terminal 35 to the other power line I4.In order to light the other illament of the lamp, the bead chain ispulled tc move the switch mechanism to the position shown by Fig. 8.Current from the power line L1 iiows 'mechanism is moved to the positionshown by Fig.9bothiilamentsofthelampareenergized inthemannerdescribedinasmuchastheshorting member and appropriate ballbearings arein electrical contact, with all three o! the iixed comtacts. Inordertotumoilthelampstheswitch mechanism is moved to theposition shown by Fig. 10,sothatthepowerlinelaisdisconnected from thecircuit through the lamp holder.

hThe elements of the lamp holder may be easily assembled by mounting thelamp socket structure and switch mechanism on the base I 2 and thenslipping the base into the shell Il. After assembling the base and shellthe cover Il is l placed in position 4and secured to the shell by vboltsIl passing through openings 16 in the base member. The switch mechanismgives a quick make and break of the circuits since as soon as the ballbearings pass the crests of the hills on the cam surfaces of theinsulating base'member l2 the springs force them downwardly intoengagement with the adjoining contacts.

What we claim as new and desire to secure by` Letters Patent oi' theUnited States is:

1. In a lamp holder, a supporting base of insulating material, lampsocket means mounted on one side of said base, a plurality oi.'stationary.. `v

contacts mounted on the other side of said base and being electricallyconnected to said socket means, a member rotatably mounted on said basehaving a plurality of recesses therein and provided with an annularperiphery having cam surfaces thereon, a ball bearing disposed in oneend of each of said recesses, a shorting member carried by saidrotatable member and overlying the other end of each of said recesses,spring means in each of said recesses engaging said snorting 3 memberand respective ball bearing and biasing "ball bearing into engagementwith a stationary contact, and means for rotating said rotatable member.said means including an operating element engaging any one of said camsurfaces.

2. In a lamp holder, a supporting base of insulating material. lampsocket means mounted on one side of said base. a plurality oi stationarycontacts mounted on the other side of said base and being electricallyconnected to said socket t means, a member rotatably mounted on saidbase having a plurality of recesses therein and provided with an annularperiphery having cam surfaces thereon; a ball bearing disposed in oneend of each of said recesses, a shorting member carried by saidrotatable member and overlying the other,- end of each'of said recesses,a plate of insulating material overlying said shorting member, springmeans in each oi' said recesses engaging said shorting member andrespective ball bearing and biasing said ball bearing into engagementwith a stationary contact, and means including an operating elementengaging said cam surfaces for rotating said rotatable member.

WILLIAM R. YOUNG. FRANK D. BRYANT.

